Take the prospective employees you are trying to place and put them in a room with only a table and two chairs.
Leave them alone for two hours, without any instruction.
At the end of that time, go back and see what they are doing.

If they have taken the table apart in that time, put them in Engineering.

If they are counting the butts in the ashtray, assign them to Finance.

If they are screaming and waving their arms, send them off to Creative.

If they are talking to the chairs, Personnel is a good spot for them.

If they are sleeping, they are Management material.

If they don't even look up when you enter the room, assign them to Security.